Textile yarn winding machines which wind yarn into packages, commonly referred to as cheeses, are known to comprise winding stations having a device for picking up the yarn end of a spinning cop to be rewound utilizing a mechanism for pneumatically loosening and transferring the yarn end of the spinning cop to a gripper tube charged with suction air which, in turn, places the yarn end into a splicing device. Winding stations embodied in this manner are known, for example, from German Patent Publications DE 38 12 643 A1 or DE 42 41 992 A1.
German Patent Publication DE 38 12 643 A1 describes a device having a cover, which encloses the spinning cop in the unwinding position, and an unwinding balloon guide disposed above the cover. A pressurized air blowing nozzle moves the yarn end from the cop to a transfer tube, which is parked in a stand-by position. The transfer tube is pivotable to move into a position centered above the unwinding balloon guide and can be charged with suction air to aspirate the yarn end from the cop. The transfer tube subsequently transfers the aspirated yarn end to a splicing device. Among other things, it is disadvantageous in this known device that the transfer tube is positioned directly in the yarn path for picking up the yarn end, which has negative effects particularly in connection with a yarn break detection circuit.
In the device in accordance with DE 42 41 992 A1 a yarn catching funnel is installed above a delivery bobbin disposed in a waiting position and transitions into a tube-shaped connecting element with a lateral aspirating opening. The yarn catcher funnel and the connecting element together have a slit-like opening facing in the cop direction through which the yarn end can pass. A pivotably seated gripper tube can be docked on the lateral aspirating opening of the connecting element to draw the yarn end into the funnel.
This known device makes it possible to prepare the yarn end of a delivery bobbin for respooling in advance so that the respooling process can be immediately started as soon as the spinning cop is moved into a respooling delivery position. However, problems can occur in this device if a yarn break occurs in a spinning cop while being unwound in the delivery position, since it is necessary for repairing the yarn break to employ the gripper tube which has already grasped the yarn end of the cop parked in the waiting position, which can lead to complications.
A further device installed at the winding stations of an automatic cheese winder is described in German Patent Publication DE 44 22 596 A1, wherein the presence of a yarn end pulled off the cop is detected by means of a sensor when the yarn is grasped by a yarn gripper element and initiates a dynamic yarn signal in the sensor to indicate the presence of the yarn end. If the presence of the yarn end is detected, a previously initiated yarn end connection process is continued, while in the absence of an appropriate yarn detection signal the yarn end connection process is interrupted and a cop changing procedure is initiated.
With this known device, the control of the yarn gripping elements required for the yarn end connection process, as well as the control of the service elements employed in connection with a cop changing process, is performed mechanically, i.e. by means of cam disk packages, which are acted upon by a common drive. Such cam disks as a rule perform a 360.degree. rotation during each yarn end connection process and accordingly are mainly designed for a predetermined direction of rotation. Hence, problems can occur with these known devices in stopping the yarn connection process in the absence of the dynamic yarn signal and returning the cam disk packages immediately into their starting "zero" position.
In addition, automatic cheese winders are known from the later published German Patent Publication DE 195 39 762.2, whose winding stations have separate drives for a yarn connection device and for a cop changing device. In this case, the drive for the cop changing device comprises a step motor, which can be controlled by a winding station computer for driving a cam disk package via a gear arrangement for actuating various manipulating devices as well as for stepping a round magazine for receiving spinning cops. By employing a separate step motor for the cop changing device, the cam disk package for the yarn connection device and the cam disk package for the cop changing device can be mechanically separated, so that a largely independent operation of the respective manipulating devices is possible, for example, with separate forward and return movements.